PDA端的数据库一般采用的是sqlce数据库

PDA端的数据库一般采用的是sqlce数据库,这样与PC端的sql2000中的数据同步就变成了一个问题,如在PDA端处理,PDA端的内存,CPU等都是一个制约因素,其次他们的一个连接稳定及其间的数据传输也是一个难点.本例中通过在PC端的转化后再复制到PDA上面,这样,上面所有的问题都得到了一个有效的控制.

一,创建项目,添加引用 

二 设计界面,编写代码

程序代码

 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlServerCe;
using OpenNETCF.Desktop.Communication;
using System.IO;
using System.Collections;

namespace FyfjmFileChange
{
    public partial class MainForm : Form
    {
        string _strCurrentDirectory = System.IO.Directory.GetCurrentDirectory();
        RAPI m_rapi = new RAPI();
        private ArrayList _arrData = new ArrayList();
        private string[] Temp;
        private int sign;

        public MainForm()
        {
            InitializeComponent();
        }

        private void btOpenFile_Click(object sender, EventArgs e)
        {
            if (openFileDialog.ShowDialog() == DialogResult.OK)
            {
                tbSourceLoadFile.Text = openFileDialog.FileName;
            }
        }

        private void btSaveFile_Click(object sender, EventArgs e)
        {
            if (saveFileDialog.ShowDialog() == DialogResult.OK)
            {
                tbLoadPurposeFile.Text = saveFileDialog.FileName;
            }
        }

        private void btUp1Load_Click(object sender, EventArgs e)
        {
            sign = 1;
            lbDownLoadState.Text = "Status：Ready Up……";

            Cursor.Current = Cursors.WaitCursor;

            DataAcess.DisConnection();

            if (tbLoadPurposeFile.Text.Trim().Length > 0 && tbPdaSourceFile.Text.Trim().Length > 0)
            {
                try
                {
                    lbDownLoadState.Text = "Status：Copying the File……";

                    m_rapi.Connect(false, -1);
                    m_rapi.CopyFileFromDevice(_strCurrentDirectory + @"DataBaseFyfjm.sdf", tbPdaSourceFile.Text.Trim() + @"DataBaseFyfjm.sdf", true);
                    m_rapi.Disconnect();

                    lbDownLoadState.Text = "Status：Changing the File……";

                    if (FileFormCeDataBase(tbLoadPurposeFile.Text.Trim()))
                    {
                        MessageBox.Show("File Update successful", "System Message");

                        lbDownLoadState.Text = "Status:Successful……";
                    }
                    else
                    {
                        MessageBox.Show("DataFile Change Failed", "System Message");

                        lbDownLoadState.Text = "Status:Failed……";
                    }
                }
                catch (RAPIException ex)
                {
                    System.Windows.Forms.MessageBox.Show(ex.Message, "System Message");

                    lbDownLoadState.Text = "Status:Failed……";
                }
            }

            Cursor.Current = Cursors.Default;
        }

        private void btDownLoadStop_Click(object sender, EventArgs e)
        {
            Close();
        }

        private void btDownLoad_Click(object sender, EventArgs e)
        {
            Cursor.Current = Cursors.WaitCursor;

            if (tbSourceLoadFile.Text.Trim().Length > 0 && tbPdaPurposeFile.Text.Trim().Length > 0)
            {
                if (MessageBox.Show("Are you Sure to clear the SKU data", "System Message", MessageBoxButtons.OKCancel, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2) == DialogResult.OK)
                {
                    try
                    {
                        SqlCeConnection _objConn = DataAcess.CreateConnection(_strCurrentDirectory + @"DataBaseFyfjm.sdf");
                        string _strSQL = "delete from Enquiry";

                        SqlCeCommand _objComm = _objConn.CreateCommand();
                        _objComm.CommandText = _strSQL;
                        _objComm.CommandType = CommandType.Text;
                        _objComm.ExecuteNonQuery();
                    }
                    catch (SqlCeException ex)
                    {
                        MessageBox.Show("Delete data Failed " + ex.Message, "System Message", MessageBoxButtons.OK, MessageBoxIcon.Exclamation, MessageBoxDefaultButton.Button1);
                        return;
                    }
                }

                if (File.Exists(tbSourceLoadFile.Text.Trim()) && FileToCeDataBase(tbSourceLoadFile.Text.Trim()))
                {
                    try
                    {
                        DataAcess.Dispose();           //在复制之前要关闭数据库
                        //                        while (DataAcess._objConn.State == ConnectionState.Closed)
                        //                        {
                        m_rapi.Connect(false, -1);
                        m_rapi.CopyFileToDevice(_strCurrentDirectory + @"DataBaseFyfjm.sdf", tbPdaPurposeFile.Text.Trim() + @"DataBaseFyfjm.sdf", true);
                        m_rapi.Disconnect();
                        MessageBox.Show("Down File to device successful", "System Message");
                        //                        }
                    }
                    catch (RAPIException ex)
                    {
                        System.Windows.Forms.MessageBox.Show(ex.Message, "System Message");
                    }
                    //}
                }
                else
                {
                    MessageBox.Show("The SourceFile not exist", "System Message", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
                }

                Cursor.Current = Cursors.Default;
                DownLoadProgressBar.Value = 0;
            }
        }

        private void UpStop_Click(object sender, EventArgs e)
        {
            Close();
        }

        private bool SaveTxt(string strFilePath)
        {
            bool _bResult = false;
            DataSet _objDs = new DataSet();
            try
            {
                SqlCeConnection _objConn = DataAcess.CreateConnection(_strCurrentDirectory + @"DataBaseFyfjm.sdf");
                SqlCeCommand _objComm = _objConn.CreateCommand();
                _objComm.CommandText = "SELECT SKU FROM Take where Take_sign =  '0'";
                _objComm.CommandType = CommandType.Text;
                SqlCeDataAdapter _objDa = new SqlCeDataAdapter(_objComm);
                SqlCeCommandBuilder _objCb = new SqlCeCommandBuilder(_objDa);
                _objDa.Fill(_objDs);

                UpLoadProgressBar.Maximum = _objDs.Tables[0].Rows.Count;
                UpLoadProgressBar.Step = 0;

                System.IO.StreamWriter _objWriter = new StreamWriter(strFilePath, false, System.Text.Encoding.UTF8);

                int i = 0;
                foreach (DataRow _objDr in _objDs.Tables[0].Rows)
                {
                    string _sLine = _objDr[0] + "," + "1";
                    _objWriter.WriteLine(_sLine);

                    i++;
                    UpLoadProgressBar.Value = i;
                }
                _objWriter.Close();

                DataAcess.Close();
                _objConn.Close();
                _objConn.Dispose();
                _objConn = null;
                _objComm.Dispose();
                _bResult = true;
                
            }
            catch (SqlCeException ex)
            {
                MessageBox.Show(ex.Message, "系统提示：", MessageBoxButtons.OK, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1);
            }
            catch (Exception ex1)
            {
                MessageBox.Show(ex1.Message, "系统提示：", MessageBoxButtons.OK, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1);
            }

            return _bResult;
        }

        private bool FileFormCeDataBase(string strFilePath)
        {
            bool _bResult = false;
            string[] _strTemp = strFilePath.Split('.');
            string _strFileStype = _strTemp[_strTemp.Length - 1];
            switch (_strFileStype.ToUpper())
            {
                /*case "XLS":
                    _bResult = SaveXLS(strFilePath);
                    break;
                case "CSV":
                    _bResult = SaveCSV(strFilePath);
                    break;*/
                case "TXT":
                    switch (sign)
                    {
                        case 1:
                            _bResult = SaveTxt(strFilePath);
                            break;
                        case 2:
                            _bResult = SumSaveTxt(strFilePath);
                            break;
                        case 3:
                            _bResult = AllSaveTxt(strFilePath);
                            break;
                        default:
                            break;
                    }
                    break;
                default:
                    {
                        MessageBox.Show("File Format Error", "System Message", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
                        break;
                    }
            }

            UpLoadProgressBar.Value = 0;

            return _bResult;
        }

        private bool FileToCeDataBase(string strFilePath)
        {
            bool _bResult = false;
            try
            {
                _arrData = new ArrayList();
                System.IO.StreamReader objectReader = new System.IO.StreamReader(strFilePath, System.Text.Encoding.UTF8);
                string sLine = "";

                while (sLine != null)
                {
                    sLine = objectReader.ReadLine();
                    if (sLine != null)
                    {
                        _arrData.Add(sLine);
                    }
                }
                objectReader.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "系统提示", MessageBoxButtons.OK, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1);
            }

            SqlCeConnection _objConn = DataAcess.CreateConnection(_strCurrentDirectory + @"DataBaseFyfjm.sdf");
            SqlCeCommand _objComm = _objConn.CreateCommand();

            DownLoadProgressBar.Maximum = _arrData.Count;
            DownLoadProgressBar.Step = 1;

            for (int j = 0; j < _arrData.Count; j++)
            {
                Temp = _arrData[j].ToString().Trim().Split(',');
                _objComm.CommandText = string.Format("insert into Enquiry(Code,Color,Size,Price,SKU) values('{0}','{1}','{2}','{3}','{4}')", Temp[0].Trim(), Temp[1].Trim(), Temp[2].Trim(), Temp[3].Trim(), Temp[4].Trim());
                _objComm.ExecuteNonQuery();

                DownLoadProgressBar.Value++;
            }
            _arrData.Clear();
            _bResult = true;

            _objConn.Close();
            _objConn.Dispose();
            _objConn = null;
            _objComm.Dispose();
            return _bResult;
            
        }

        private void btUp2Load_Click(object sender, EventArgs e)
        {
            sign = 2;
            lbDownLoadState.Text = "Status：Ready Up……";

            Cursor.Current = Cursors.WaitCursor;

            DataAcess.DisConnection();

            if (tbLoadPurposeFile.Text.Trim().Length > 0 && tbPdaSourceFile.Text.Trim().Length > 0)
            {
                try
                {
                    lbDownLoadState.Text = "Status：Copying the File……";

                    m_rapi.Connect(false, -1);
                    m_rapi.CopyFileFromDevice(_strCurrentDirectory + @"DataBaseFyfjm.sdf", tbPdaSourceFile.Text.Trim() + @"DataBaseFyfjm.sdf", true);
                    m_rapi.Disconnect();

                    lbDownLoadState.Text = "Status：Changing the File……";

                    if (FileFormCeDataBase(tbLoadPurposeFile.Text.Trim()))
                    {
                        MessageBox.Show("File Update successful", "System Message");

                        lbDownLoadState.Text = "Status:Successful……";
                    }
                    else
                    {
                        MessageBox.Show("DataFile Change Failed", "System Message");

                        lbDownLoadState.Text = "Status:Failed……";
                    }
                }
                catch (RAPIException ex)
                {
                    System.Windows.Forms.MessageBox.Show(ex.Message, "System Message");

                    lbDownLoadState.Text = "Status:Failed……";
                }
            }

            Cursor.Current = Cursors.Default;
        }

        private bool SumSaveTxt(string strFilePath)
        {
            bool _bResult = false;
            DataSet _objDs = new DataSet();
            try
            {
                SqlCeConnection _objConn = DataAcess.CreateConnection(_strCurrentDirectory + @"DataBaseFyfjm.sdf");
                SqlCeCommand _objComm = _objConn.CreateCommand();
                _objComm.CommandText = "select SKU,Count(*)as Qty from Take where Take_sign = '0' Group By SKU";
                _objComm.CommandType = CommandType.Text;
                SqlCeDataAdapter _objDa = new SqlCeDataAdapter(_objComm);
                SqlCeCommandBuilder _objCb = new SqlCeCommandBuilder(_objDa);
                _objDa.Fill(_objDs);

                UpLoadProgressBar.Maximum = _objDs.Tables[0].Rows.Count;
                UpLoadProgressBar.Step = 0;

                System.IO.StreamWriter _objWriter = new StreamWriter(strFilePath, false, System.Text.Encoding.UTF8);

                int i = 0;
                foreach (DataRow _objDr in _objDs.Tables[0].Rows)
                {
                    string _sLine = _objDr[0] + "," + _objDr[1];
                    _objWriter.WriteLine(_sLine);

                    i++;
                    UpLoadProgressBar.Value = i;
                }
                _objWriter.Close();

                DataAcess.Close();
                _objConn.Close();
                _objConn.Dispose();
                _objConn = null;
                _objComm.Dispose();
                _bResult = true;

            }
            catch (SqlCeException ex)
            {
                MessageBox.Show(ex.Message, "系统提示：", MessageBoxButtons.OK, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1);
            }
            catch (Exception ex1)
            {
                MessageBox.Show(ex1.Message, "系统提示：", MessageBoxButtons.OK, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1);
            }

            return _bResult;
        }

        private void btTake_Click(object sender, EventArgs e)
        {
            Cursor.Current = Cursors.WaitCursor;
            if (MessageBox.Show("Are you Sure to clear the Stock Take data", "System Message", MessageBoxButtons.OKCancel, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2) == DialogResult.OK)
            {
                try
                {
                    SqlCeConnection _objConn = DataAcess.CreateConnection(_strCurrentDirectory + @"DataBaseFyfjm.sdf");
                    string _strSQL1 = "delete from Take";

                    SqlCeCommand _objComm = _objConn.CreateCommand();
                    _objComm.CommandText = _strSQL1;
                    _objComm.CommandType = CommandType.Text;
                    _objComm.ExecuteNonQuery();

                    DataAcess.Dispose();           //在复制之前要关闭数据库
                    m_rapi.Connect(false, -1);
                    m_rapi.CopyFileToDevice(_strCurrentDirectory + @"DataBaseFyfjm.sdf", tbPdaPurposeFile.Text.Trim() + @"DataBaseFyfjm.sdf", true);
                    m_rapi.Disconnect();
                    MessageBox.Show("Delete Successful!", "System Message", MessageBoxButtons.OK, MessageBoxIcon.Information, MessageBoxDefaultButton.Button1);
                }
                catch (SqlCeException ex)
                {
                    MessageBox.Show("Delete data Failed " + ex.Message, "System Message", MessageBoxButtons.OK, MessageBoxIcon.Exclamation, MessageBoxDefaultButton.Button1);
                    return;
                }
            }
            Cursor.Current = Cursors.Default;
        }

        private void btAllclear_Click(object sender, EventArgs e)
        {
            if (MessageBox.Show("Are you Sure to clear all the data", "System Message", MessageBoxButtons.OKCancel, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2) == DialogResult.OK)
            {
                try
                {
                    SqlCeConnection _objConn = DataAcess.CreateConnection(_strCurrentDirectory + @"DataBaseFyfjm.sdf");
                    string _strSQL = "delete from Take";
                    string _strSQL1 = "delete from Enquiry";

                    SqlCeCommand _objComm = _objConn.CreateCommand();
                    _objComm.CommandText = _strSQL;
                    _objComm.CommandType = CommandType.Text;
                    _objComm.ExecuteNonQuery();

                    _objComm.CommandText = _strSQL1;
                    _objComm.CommandType = CommandType.Text;
                    _objComm.ExecuteNonQuery();

                    DataAcess.Dispose();           //在复制之前要关闭数据库
                    m_rapi.Connect(false, -1);
                    m_rapi.CopyFileToDevice(_strCurrentDirectory + @"DataBaseFyfjm.sdf", tbPdaPurposeFile.Text.Trim() + @"DataBaseFyfjm.sdf", true);
                    m_rapi.Disconnect();

                    MessageBox.Show("Delete Successful!", "System Message", MessageBoxButtons.OK, MessageBoxIcon.Information, MessageBoxDefaultButton.Button1);
                }
                catch (SqlCeException ex)
                {
                    MessageBox.Show("Delete data Failed " + ex.Message, "System Message", MessageBoxButtons.OK, MessageBoxIcon.Exclamation, MessageBoxDefaultButton.Button1);
                    return;
                }
            }
        }

        private void btUp3Load_Click(object sender, EventArgs e)
        {
            sign = 3;
            lbDownLoadState.Text = "Status：Ready Up……";

            Cursor.Current = Cursors.WaitCursor;

            DataAcess.DisConnection();

            if (tbLoadPurposeFile.Text.Trim().Length > 0 && tbPdaSourceFile.Text.Trim().Length > 0)
            {
                try
                {
                    lbDownLoadState.Text = "Status：Copying the File……";

                    m_rapi.Connect(false, -1);
                    m_rapi.CopyFileFromDevice(_strCurrentDirectory + @"DataBaseFyfjm.sdf", tbPdaSourceFile.Text.Trim() + @"DataBaseFyfjm.sdf", true);
                    m_rapi.Disconnect();

                    lbDownLoadState.Text = "Status：Changing the File……";

                    if (FileFormCeDataBase(tbLoadPurposeFile.Text.Trim()))
                    {
                        MessageBox.Show("File Update successful", "System Message");

                        lbDownLoadState.Text = "Status:Successful……";
                    }
                    else
                    {
                        MessageBox.Show("DataFile Change Failed", "System Message");

                        lbDownLoadState.Text = "Status:Failed……";
                    }
                }
                catch (RAPIException ex)
                {
                    System.Windows.Forms.MessageBox.Show(ex.Message, "System Message");

                    lbDownLoadState.Text = "Status:Failed……";
                }
            }

            Cursor.Current = Cursors.Default;
        }

        private bool AllSaveTxt(string strFilePath)
        {
            bool _bResult = false;
            DataSet _objDs = new DataSet();
            try
            {
                SqlCeConnection _objConn = DataAcess.CreateConnection(_strCurrentDirectory + @"DataBaseFyfjm.sdf");
                SqlCeCommand _objComm = _objConn.CreateCommand();
                _objComm.CommandText = "select SKU,Zone,Take_sign from Take";
                _objComm.CommandType = CommandType.Text;
                SqlCeDataAdapter _objDa = new SqlCeDataAdapter(_objComm);
                SqlCeCommandBuilder _objCb = new SqlCeCommandBuilder(_objDa);
                _objDa.Fill(_objDs);

                UpLoadProgressBar.Maximum = _objDs.Tables[0].Rows.Count;
                UpLoadProgressBar.Step = 0;

                System.IO.StreamWriter _objWriter = new StreamWriter(strFilePath, false, System.Text.Encoding.UTF8);

                int i = 0;
                foreach (DataRow _objDr in _objDs.Tables[0].Rows)
                {
                    string _sLine = _objDr[1] + "," + _objDr[0] + "," + "1" + "," + _objDr[2];
                    _objWriter.WriteLine(_sLine);

                    i++;
                    UpLoadProgressBar.Value = i;
                }
                _objWriter.Close();

                DataAcess.Close();
                _objConn.Close();
                _objConn.Dispose();
                _objConn = null;
                _objComm.Dispose();
                _bResult = true;

            }
            catch (SqlCeException ex)
            {
                MessageBox.Show(ex.Message, "系统提示：", MessageBoxButtons.OK, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1);
            }
            catch (Exception ex1)
            {
                MessageBox.Show(ex1.Message, "系统提示：", MessageBoxButtons.OK, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1);
            }

            return _bResult;
        }

    }
}

本文来自互联网用户投稿，该文观点仅代表作者本人，不代表本站立场。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如若转载，请注明出处：http://www.mzph.cn/news/389222.shtml

如若内容造成侵权/违法违规/事实不符，请联系多彩编程网进行投诉反馈email:809451989@qq.com，一经查实，立即删除！

相关文章

bzoj 1016 [JSOI2008]最小生成树计数——matrix tree（相同权值的边为阶段缩点）（码力）...

bzoj 1016 [JSOI2008]最小生成树计数——matrix tree（相同权值的边为阶段缩点）（码力）...

题目&#xff1a;https://www.lydsy.com/JudgeOnline/problem.php?id1016 就是缩点&#xff0c;每次相同权值的边构成的联通块求一下matrix tree。注意gauss里的编号应该是从1到...的连续的。 学习了一个TJ。用了vector。自己曾写过一个只能过样例的。都放上来吧。 路径压缩的…
阅读更多...
商米

商米

2019独角兽企业重金招聘Python工程师标准>>> 今天看了一下商米的官网&#xff0c;发现他家的东西还真的是不错。有钱了&#xff0c;想去体验一下。 如果我妹妹还有开便利店的话&#xff0c;我会推荐他用这个。小巧便捷&#xff0c;非常方便。 转载于:https://my.osc…
阅读更多...
python交互式和文件式_使用Python创建和自动化交互式仪表盘

python交互式和文件式_使用Python创建和自动化交互式仪表盘

python交互式和文件式In this tutorial, I will be creating an automated, interactive dashboard of Texas COVID-19 case count by county using python with the help of selenium, pandas, dash, and plotly. I am assuming the reader has some familiarity with python,…
阅读更多...
不可不说的Java“锁”事

不可不说的Java“锁”事

2019独角兽企业重金招聘Python工程师标准>>> 前言 Java提供了种类丰富的锁&#xff0c;每种锁因其特性的不同&#xff0c;在适当的场景下能够展现出非常高的效率。本文旨在对锁相关源码&#xff08;本文中的源码来自JDK 8&#xff09;、使用场景进行举例&#xff0c…
阅读更多...
数据可视化 信息可视化_可视化数据以帮助清理数据

数据可视化 信息可视化_可视化数据以帮助清理数据

数据可视化 信息可视化The role of a data scientists involves retrieving hidden relationships between massive amounts of structured or unstructured data in the aim to reach or adjust certain business criteria. In recent times this role’s importance has been…
阅读更多...
seaborn添加数据标签_常见Seaborn图的数据标签快速指南

seaborn添加数据标签_常见Seaborn图的数据标签快速指南

seaborn添加数据标签In the course of my data exploration adventures, I find myself looking at such plots (below), which is great for observing trend but it makes it difficult to make out where and what each data point is.在进行数据探索的过程中&#xff0c;我…
阅读更多...
使用python pandas dataframe学习数据分析

使用python pandas dataframe学习数据分析

⚠️ Note — This post is a part of Learning data analysis with python series. If you haven’t read the first post, some of the content won’t make sense. Check it out here.Note️ 注意 -这篇文章是使用python系列学习数据分析的一部分。 如果您还没有阅读第一篇文…
阅读更多...
无向图g的邻接矩阵一定是_矩阵是图

无向图g的邻接矩阵一定是_矩阵是图

无向图g的邻接矩阵一定是To study structure,tear away all flesh soonly the bone shows.要研究结构&#xff0c;请尽快撕掉骨头上所有的肉。 Linear algebra. Graph theory. If you are a data scientist, you have encountered both of these fields in your study or work …
阅读更多...
前端绘制绘制图表_绘制我的文学风景

前端绘制绘制图表_绘制我的文学风景

前端绘制绘制图表Back when I was a kid, I used to read A LOT of books. Then, over the last couple of years, movies and TV series somehow stole the thunder, and with it, my attention. I did read a few odd books here and there, but not with the same ferocity …
阅读更多...
如何描绘一个vue的项目_描绘了一个被忽视的幽默来源

如何描绘一个vue的项目_描绘了一个被忽视的幽默来源

如何描绘一个vue的项目Source)来源 ) Data visualization is a great way to celebrate our favorite pieces of art as well as reveal connections and ideas that were previously invisible. More importantly, it’s a fun way to connect things we love — visualizing …
阅读更多...
数据存储加密和传输加密_将时间存储网络应用于加密预测

数据存储加密和传输加密_将时间存储网络应用于加密预测

数据存储加密和传输加密I’m not going to string you along until the end, dear reader, and say “Didn’t achieve anything groundbreaking but thanks for reading ;)”.亲爱的读者&#xff0c;我不会一直待到最后&#xff0c;然后说&#xff1a; “没有取得任何开创性的…
阅读更多...
熊猫分发_熊猫新手：第一部分

熊猫分发_熊猫新手：第一部分

熊猫分发For those just starting out in data science, the Python programming language is a pre-requisite to learning data science so if you aren’t familiar with Python go make yourself familiar and then come back here to start on Pandas.对于刚接触数据科学的…
阅读更多...
多线程 进度条 C# .net

多线程 进度条 C# .net

前言　　在我们应用程序开发过程中&#xff0c;经常会遇到一些问题&#xff0c;需要使用多线程技术来加以解决。本文就是通过几个示例程序给大家讲解一下多线程相关的一些主要问题。 执行长任务操作　　许多种类的应用程序都需要长时间操作&#xff0c;比如&#xff1a;执行一…
阅读更多...
《Linux内核原理与分析》第六周作业

《Linux内核原理与分析》第六周作业

课本&#xff1a;第五章 系统调用的三层机制&#xff08;下&#xff09; 中断向量0x80和system_call中断服务程序入口的关系 0x80对应着system_call中断服务程序入口&#xff0c;在start_kernel函数中调用了trap_init函数&#xff0c;trap_init函数中调用了set_system_trap_gat…
阅读更多...
Codeforces Round 493

Codeforces Round 493

心情不好&#xff0c;被遣散回学校 &#xff0c;心态不好 &#xff0c;为什么会累&#xff0c;一直微笑就好了 #include<bits/stdc.h> using namespace std; int main() {freopen("in","r",stdin);\freopen("out","w",stdout);i…
阅读更多...
android动画笔记二

android动画笔记二

从android3.0&#xff0c;系统提供了一个新的动画&#xff0d;property animation, 为什么系统会提供这样一个全新的动画包呢&#xff0c;先来看看之前的补间动画都有什么缺陷吧1、传统的补间动画都是固定的编码&#xff0c;功能是固定的&#xff0c;扩展难度大。比如传统动画只…
阅读更多...
回归分析检验_回归分析

回归分析检验_回归分析

回归分析检验Regression analysis is a reliable method in statistics to determine whether a certain variable is influenced by certain other(s). The great thing about regression is also that there could be multiple variables influencing the variable of intere…
阅读更多...
是什么样的骚操作让应用上线节省90%的时间

是什么样的骚操作让应用上线节省90%的时间

优秀的程序员 总会想着 如何把花30分钟才能解决的问题 在5分钟内就解决完 例如在应用上线这件事上 通常的做法是 构建项目在本地用maven打包 每次需要clean一次&#xff0c;再build一次 部署包在本地ide、git/svn、maven/gradie 及代码仓库、镜像仓库和云平台间 来回切换 上传部…
阅读更多...
Ubuntu 18.04 下如何配置mysql 及 配置远程连接

Ubuntu 18.04 下如何配置mysql 及 配置远程连接

首先是大家都知道的老三套&#xff0c;啥也不说上来就放三个大招&#xff1a; sudo apt-get install mysql-serversudo apt isntall mysql-clientsudo apt install libmysqlclient-dev 这三步下来mysql就装好了&#xff0c;然后我们偷偷检查一下 sudo netstat -tap | grep mysq…
阅读更多...
数据科学与大数据技术的案例_主数据科学案例研究，招聘经理的观点

数据科学与大数据技术的案例_主数据科学案例研究，招聘经理的观点

数据科学与大数据技术的案例I’ve been in that situation where I got a bunch of data science case studies from different companies and I had to figure out what the problem was, what to do to solve it and what to focus on. Conversely, I’ve also designed case…
阅读更多...
推荐文章
最新文章

Copyright @ 2022~2023